Chuck feature of tools of the detachably connected shank and handle type



May 13, 1952 2,596,594

J- N. PETRE CHUCK FEATURE OF TOOLS OF THE DETAC LY ONNECTED SHANK ANDHANDLE TYP Filed 001;. 11, 1950 1 F14. FJ'. 0 351 153 2 1 Q2 F195. I aBag;

3nvemor Jo/z .Pefre,

(Ittomeg Patented May 13, 1952 CHUCK FEATURE OF TOOLS OF THE DE-TACHABLY CONNECTED SHANK AND HAN DLE TYPE John N. Petre, Orchard Park,N. Y., assignor to Park Metalware Company, Inc., Orchard Park, N. Y., acorporation of New York Application October 11, 1950, Serial No. 189,554

1 Claim. 1

This invention relates to tools of the type wherein a tool shankprojects from and is coaxial with a handle, is mounted within a sleevefitted within a recess formed axially in the handle, and is secured inthe sleeve and thereby in the handle in detachable relation. Sundryvarying tool elements, e. g. screw drivers of different forms, socketwrenches and the like may be interchangeably used with the same handleand may be of either single shank or double shank construction, thedouble shank elements having different tool formations at their oppositeends and being reversible in relation to the handle whereby either toolformation, according to choice, may be used.

A tool of the above description which has been standard for at least ageneration and has had wide acceptance by the trade and the public isone wherein the shank is provided with a flat faced collar of greaterdiametrical dimension, the collar being conventionally hexagonal incross section and carrying a spring loaded ball friction latch whichprojects to a suitable extent beyond a flat face of the collar and isbiased in a radial direction for latching cooperation with the wall ofthe sleeve in which the collar is fitted.

This invention specifically relates to tools as above described whichhave the standard feature of a fiat faced collar of greater diametricaldimension than the shank.

Tools which are provided with the ball latch feature as above describedhave been found to be seriously objectionable from a number ofstandpoints. The manufacturing operation is expensive in that itinvolves the necessity of drilling a recess for the spring and balllatch followed by an upsetting operation to deform the edge of therecess whereby to prevent the displacement of the latch. In manufacture,due to unavoidable adventitious circumstances, it happens in asubstantial number of instances that the ball latch will not project insuitable degree beyond the fiat faced collar, a fact which imposes amanufacturing loss. In use, moisture seeps into the recess for the balllatch, causing rusting of the spring. Fine particles of dust, dirt orgrease also work into such recess and impair the action of the balllatch. Repair is so diflicult as to be prohibitive in cost. In general,inasmuch as the active element of the latch is carried by the shank, ithas been found to be more economical in cases where repair is indicatedto discard the shank and replace it with a new one.

The entire problem in connection with tools as described in the firstparagraph of the specification involves considerations of manufacture,use and repair.

The improvement originated by me and John 0. Olsen, as joint inventors,and which :is disclosed in Patent 2,476,762 issued July 19, 1949,satisfactorily solves certain, but by no means all, of the aspects ofthe problem. This patented improvement dis-closes a species whichsatisfactorily overcomes the objections of the ball latch feature inrespect to use, repair and certain manufacturing problems.

However, from a manufacturing standpoint, the improvement shown in saidpatent falls short of an important advantage of the ball latchconstruction in that, as a proposition of use and of consequentmanufacture, it is required that the shanks of the tools of the typeabove generally described be of varying standard diameters and it isfurther required that the sleeves which are fitted in the handles bedimensioned to accord with variations in the maximum width of the keysformed on the shanks, such width varying in accordance with variationsin the diameters of the shanks.

It follows that a handle having a sleeve which accords with a shank ofsome particular diameter will be quite useless in connection with ashank of another particular diameter. Therefore for the shanks ofvarying standard diameters handles having sleeves of correspondingvarying internal diameters are required. In short a standard handle isimpossible and a particular handle must be provided for each diameter ofshank.

On the other hand, from a manufacturing standpoint, the ball latchconstruction has the advantage that regardless of variations in standardshank diameters the flat faced collar may be of a single standarddiameter and hence the sleeves in the handles which accommodate thecollars may be of a conforming single standard diameter. It follows thatthe handles may be standardized and any handle may be used for thecompletion of a tool regardless of the particular standard diameter ofthe shank.

The invention is directed to the chuck features of tools of the typegenerally above described as characterized by a shank-carried flat facedcollar of greater diametrical dimension.

The object of the invention is a construction which satisfactorily dealswith all aspects of the entire problem of manufacture, use and repair.

The invention is characterized by certain novel features of ahandle-carried leaf spring latch and associated parts, the latch beingin cooperation with a flat face of the shank-carried collar. Theinvention is of advantage in enabling the economical repair of toolsembodying the standard ball latch feature and is also of advantage inthe '2 and abuts-the shoulder 5.

aueaeoe manufacture of tools embodying the feature of the flat facedcollar of greater diameter than the shank in which manufacture the balllatch feature may be entirely omitted. Further characterizing details ofthe features of the invention will be set forth asthe descriptionproceeds;

In the accompanying drawings:

Figure 1 is an elevation partly in section of a tool in accordance withthe invention in which two tool elements are formed, respectively, atthe ends of a double shank.

Figure 2 is a similar view partly in section along the line 2-2 ofFigure 1.

Figure 3 is a detail longitudinal section in the same plane as Figure 2,showing the position of the spring latch when the hexagonal collar ofthe tool is in place.

Figure 4 is a view similar to Figure 3, showing in detail the positionof the spring latch when the tool shank is removed.

Figure 5 is a view similar to Figures 3 and 4 showing the improvement inrelation to a tool shank provided with a ball latch.

Figure 6 is a cross section along the line E-5 ofFigure 3.

Figure '7 is a perspective view showing the spring latch and the sleevein separated relation.

The tool handle I has no intrinsic novelty. It ismade by a moldingprocess from any suitable plastic material, for example a phenoliccondensation compound, and is formed with a central axial recess 2 ofsuitable extent, open to its inner end, the recess 2 being of circularcross section. In accordance with well known practice a metallic sleeve3 is fitted in the recess 2. The sleeve 3 includes a pilot part A ofannular cross section and aflat faced part 5 of greater diameter andpreferably of hexagonal cross section. At a suitable distance from theinner end of the :handle the recess 2 is formed with an annular shoulder6, and between the inner end of the handle and the shoulder 6, therecess is formed with a second annular shoulder i of greater diameterthan the shoulderfi, the recess thus having a portion of maximumdiameter 8 extending from the. inner end of the handle and a portion 9of less diameter extending from the shoulderB to the shoulder l. Thepilot part d of the sleeve 3 fits in the portion 3 of the recess Thehexagonal part 5 .of the sleeve 3 fits in the portion 8 ofthe recess gand abuts the shoulder l. The sleeve 3, inaccordance with standardpractice, has a press fit within the portions 3 and 9 of the recess 2and, except in respects to be herein described, is of standardconstruction.

Since the portion 8 of the recess 2 is of circular cross section and thepart 5 of the sleeve 3 is of hexagonalcross section the flat externalfaces of the part 5 have a chord-like relation to the,

annular face of the recess portion 3 whereby ,filfiarances H! areprovided between the several flat faces of the part 5 and the annularwall of the recess portion 8. In the prior construction these clearanceshave been adventitious and non-functional.

The tool is completed by a shank i I which may beeither of single formor double form. A double shank is shown and is formed at its ends withdiverse tool elements l2, either of which maybe used according tochoice. The shank ll carriesa flat faced collar l3 which is preferably[of the standard hexagonal form and is rigidly The fitted upon the shankin the usual manner. collar l3 has diametrical dimension substantiallygreater than the diametrical dimensions of the shank. Where the shank isof single form it 1s provided with but a single terminal tool elementand the collar is located at or near its inner end. Where the shank isof double form the collar is located substantially midway between thetool elements. The internal conformation of the part 5 corresponds tothe cross sectional outline of the collar I3. In the construction asshown and preferred the part 5 is of hexagonal cross section, bot hinternal and externally. The sleeve 3 is formed internally at thejunction of the parts 4 and 5 with an annular shoulder l4 against whichthe end of the collar l3 bears and which limits the insertion movementof the collar into the sleeve.

In accordance with the invention the shank is securely held againstaccidental displacement from the sleeve 3 by a novel latch l5 of leafspring form, the outer terminal of which is formed to bear with suitablepressure against a flat surface of the collar I3 and thereby to opposeadequate frictional resistance to the axial displacement of the collarfrom the sleeve while at the same time permitting the ready manualseparation of the shank from the handle.

The latch consists of a straight elongated body of thin spring metalwhich is formed'at ts inner end with an inturned flange l6 and at itsouter end with an inwardly directed terminal bow H which constitutes theactive element of the latch and is the part which bears frictionallyupon a flat face of the collar l3, the bow I being or" substantialsemi-circular outline in l-on: gitudinal section. The elongated body ofthe latch l5 overliesthe sleeve 3 (without the .necese.

sity of attachment to it) in longitudinally ex:-v tencling'relation andthe flange l6 abuts the in: ner end of the sleeve and is held in clampedrelation between it and the shoulder 6, displacemerit of the latch ineither longitudinal direction bei ther p even ed- The pa o the sleeve isformed in one of its flat faces with elongated slot it and the bow llextendsinto the slot and thereby engages the hat face of the collar I3.When the sleeve is inserted into the recess 2 the straight body of thelatch cuts a keyway, so to speak, in the portion 9 of the recess 2. Thestraight body of the latch is in effect clamped between theflat face ofthe part 5 which is located behind the slot 18 and the wall of theportion 8 of the recess 2. In this relation the clearances i0 arefunctional that any one of them may serve for the accommodationpof thatpart of the latch which overlies the slot-provided fiat face of the part5 of the sleeve. The keyway out by the latch, the projection of the bowll into the slot 18 and the clamping of the body of the latch preventsthe latch from shifting peripherally relatively to the sleeve.

The normal tendency of the bow-provided terminal portion of the latch i5is to spring inward whereby, the shank being removed from the halldle,the bow ll projects to some extent into the interior of the part 5 ofthe sleeve. This relation is clearly shown in Figure 4/ The rear orinner transverse wall id of the slot is provides a fulcrum about whichthe portion of the latch within the slot may'have play, the requisiteplay being provided by the clearance Ill in which the latch isaccommodated. The end of the collar is which bears against the shoulderI4 may be ideally formed on an incline, i. e. tapering, as shown at Zll.When the shank is inserted into the handle the end of the collar I3, i.e. in the construction disclosed the inclined portion 20,

acts as a shoulder with cam effect upon the how I! and springs itradially outward, thereby storing pressure in the portion of the latchwithin the slot I 8, this pressure being maintained by the engagement ofthe how I! withafiat face of the collar l3 and being of such degree asto establish a secure frictional connection of the collar 13 and thehandle whereby the shank will not be liable to axial displacement. Theslot I8 may be of such a length that the play of the portion of thelatch which is in alinement with the slot will be about a relativelylong radius whereby the spring will have a long efficient life and thetendency to crystallization at the fulcrum point 19 will be negligible.The engaged relation of the bow l1 and the collar 13 is clearly shown inFigures 3 and 5. j'

Figure 5 shows the availability of the invention for the easy andeconomical repair of tools provided with a ball latch. This figureassumes a ball latch which for one reasonor other has become inoperativein that the surface of the ball is substantially fiush with the flatface of the collar l3, that is to say, the ball does not project to anyappreciable or operative extent beyond such face. The repair isaccomplished simply by inserting into the recess 2 a sleeve 3 of theform herein shown and an associated spring latch IS, the bow l1 engagina fiat face (any flat face) of the collar l3 and thereby holding theshank securely in connected relation to the handle and completelycompensating for the inoperativeness of the ball latch.

It follows that as a proposition of original manufacture the ball latchis not required. Hence the tools as originally manufactured may be madewithout the ball latch as clearly shown in Figures 1, 2 and 3.

In the assembling operation the spring latch is simply placed withoutattachment upon the sleeve 3 to extend longitudinally thereof and withits bow I! located within the slot I B and its flange l6 abutting theend of the pilot part 5. Thereupon the sleeve, with the spring latch soassociated with it, is inserted into the recess 2 until the end of thepilot part 4 engages the shoulder l6. As above pointed out the portionof the spring latch 15 which overlies the pilot part 4 will, as thesleeve is inserted in the handle and due to the fact that the handle isof plastic material, cut a keyway in the wall of the part 9 of therecess 2. As will be readily apparent from Figures 3 and 5 the flange I8will press an accommodating groove in the shoulder 8.

In the event that after a long period of use the spring latch l5 shouldbecome crystallized or broken the tool may readily be repaired, all thatis required being the removal of the sleeve 3 from the handle, theprovision of a new spring latch and the reinsertion of the sleeve intothe handle in a manner above explained. In such insertion it is not atall important that the new spring latch be alined with the keyway cut bythe original spring latch and hence no care is required in this respect,it being immaterial that the new spring latch may be so positioned as tocut its own keyway in the wall of the part 9 of the recess 2.

I claim:

In a tool of the type which includes a handle of plastic material havingan axial recess of circular cross section, a metallic sleeve fittedwithin the recess and formed externally with a flat face in chord-likerelation to the annular wall of the recess whereby a clearance isprovided between the fiat face and the annular wall of the recess, therecess having an internal annular shoulder against which the sleeveabuts, and a shank provided with a terminal tool formation and with acollar of substantially greater diameter having a number of flat faces,the sleeve having an internal shoulder against which the collar abutsand having an internal fiat face formation conforming to the flat faceformation of the collar, the collar fitting conformably within thesleeve: a chuck construction wherein the sleeve is formed between itsexternal fiat face and a corresponding internal fiat face with anelongated longitudinally extending slot which registers with a flat faceof the collar and a spring latch is provided in association with thesleeve and is in the form of a leaf spring having a straight elongatedbody portion overlying and resting upon the sleeve and extendinglongitudinally thereof, "a terminal inwardly directed flange whichengages the inner end of the sleeve as fitted Within the recess, and aterminal bow of semi-circular outline in longitudinal section which isarranged within the slot and has a normal tendency to spring inward, theelongated body portion of the latch being clamped by and between thecollar and the annular wall of the recess and the bow-carrying terminalportion of the latch being in radial alinement with the slot with thebow normally projecting inwardly beyond the sleeve and engageable withany flat face of the collar, the clearance between the external flatface of the sleeve and the annular wall of the recess of the handleproviding radial play for the bow-carrying terminal portion of thespring latch in alinement with the slot, the inner or rear wall of theslot providing a fulcrum about which said bow-carrying terminal portionmay have its play, the inner end portion of the collar providing ashoulder which as the collar is inserted into the sleeve is engageablewith the bow of the latch with cam effect to move the bow radiallyoutward whereby to cause its engagement with the fiat face of the collaras fully inserted into the sleeve and to store power in the springlatch, the terminal flange of the spring latch being clamped by andbetween the inner end of the sleeve as fitted within the recess and theannular shoulder of the recess.

JOHN N. PETRE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,741,810 Bidal Dec. 31,1929-2,158,728 Peters May 16, 1939 2,476,762 Petre et a1 July 19, 1949FOREIGN PATENTS Number Country A Date 92,049 Sweden Apr, 14, 1938

